Thymic Neuroendocrine Tumor With Metastasis to the Breast Causing Ectopic Cushing’s Syndrome

Ectopic adrenocorticotropic hormone secretion (EAS) is responsible for approximately 10%–18% of Cushing’s syndrome cases. Thymic neuroendocrine tumors (NETs) comprise 5%–16% of EAS; therefore, they are very rare and the data about this particular tumors is scarce.

We present a case of a 34-year-old woman with a rapid onset of severe hypercortisolism in April 2016. After initial treatment with a steroid inhibitor (ketoconazole) and diagnostics including 68Ga DOTA-TATE PET/CT, it was shown to be caused by a small thymic NET.

After a successful surgery and the resolution of all symptoms, there was a recurrence after 5 years of observation caused by a metastasis to the breast, shown in the 68Ga DOTA-TATE PET/CT result and confirmed with a breast biopsy.

Treatment with a steroid inhibitor (metyrapone) and tumor resection were again curative. The last disease relapse appeared 7 years after the initial treatment, with severe hypercortisolism treated with osilodrostat. There was a local recurrence in the mediastinum, and a thoracoscopic surgery was performed with good clinical and biochemical effect.

The patient remains under careful follow-up. Our case stays in accordance with recent literature data, showing that patients with thymic NETs are younger than previously considered and that the severity of hypercortisolism does not correlate with the tumor size. The symptoms of EAS associated with thymic NET may develop rapidly and may be severe as in our case. Nuclear medicine improves the effectiveness of the tumor search, which is crucial in successful EAS therapy. Our case also underlines the need for lifelong monitoring of patients with thymic NETs and EAS.

1 Introduction

Ectopic adrenocorticotropic hormone secretion (EAS) represents between 9% and 18% of adrenocorticotropic hormone (ACTH)-dependent Cushing’s syndrome (CS) cases (13). The tumors secreting ACTH may occur in many locations and present with different histopathological differentiation, resulting in various clinical outcomes. In the past, most of the EAS cases were associated with small cell lung cancer, characterized by rapid tumor progression and unfavorable prognosis. Recently, well-differentiated neuroendocrine tumors (NETs) from the foregut prevail in the clinical series of EAS, with most common locations in the lungs, thymus, and pancreas (1).

EAS is often associated with severe hypercortisolism. Typical Cushing’s appearance may not be present due to the rapid onset of the disease. Patients with this type of hypercortisolism need urgent treatment because they have the highest mortality of all forms of CS (4). A retrospective review of 43 patients with EAS reported deaths in 27 patients (62.8%) and a median overall survival of 32.2 months. The leading causes of mortality were the progression of primary malignancies and systemic infections; two patients died from pulmonary embolism (5).

Prompt surgical removal of the tumor secreting ACTH is the mainstay of the therapy. However, finding the tumor causing EAS can be challenging due to its small size and variety of locations. Most authors recommend a combination of computed tomography (CT) scanning of the chest, abdomen, and pelvis, with additional magnetic resonance imaging (MRI) of the pituitary, as the first-line examinations (167). However, the sensitivity of standard imaging modalities is suboptimal (8). In the analysis of 231 patients with EAS, cross-sectional imaging revealed the source of ACTH in 52.4% of them at initial evaluation, and another 29% was found during follow-up or due to nuclear medicine functional imaging, while 18.6% remained occult (9). Nuclear medicine improves the sensitivity of conventional radiology in the case of EAS, with the use of 18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT (18F-FDG PET/CT) expected to be useful in identifying EAS tumors with high proliferative activity and 68gallium-labeled somatostatin analogues (68Ga DOTA-TATE) PET/CT with the potential to detect NETs. In the head-to-head comparison, the detection rate of the source of EAS was 75% for 68Ga DOTA-TATE and 60% for 18F-FDG PET/CT, while the highest sensitivity (90%) was achieved when both methods were combined (10).

Thymic NETs comprise 2%–5% of all thymic neoplasms and may cause some paraneoplastic syndromes, with the most frequent being myasthenia gravis, syndrome of inappropriate antidiuretic hormone secretion, and hypercortisolism (11). EAS associated with thymic NETs are rare, representing between 5% and 16% of EAS in published case series (1). Because of the rarity and heterogeneity of the disease, no evidence-based guidelines are available.

We present a case of a patient with thymic NET causing EAS, with metastasis to the breast after 5 years of post-surgical remission and another local recurrence 7 years after the first operation.

Our case is unique because thymic NETs causing EAS are known as an aggressive disease with a median recurrence time of 24 months after thymectomy (12). There are only a few cases described of metastases to the breast from thymic NETs causing EAS (1316). Moreover, 68Ga-SSTR PET/CT was very helpful in detecting both primary and metastatic ectopic ACTH-secreting tumor, which underlines its role in the diagnostic workout of EAS.

2 Case description

A 32-year-old woman with no relevant medical history was admitted to the endocrinology department in April 2016 due to the rapid onset of symptoms: weight gain, hypertension, skin changes, and oligomenorrhoea.

The measurements at initial physical examination were as follows: body mass index (BMI)—29 kg/m2, blood pressure—180/90 mmHg, and heart rate—88/min. She had plethora, acne, moon face, buffalo hump, central obesity, many red striae in the abdominal area, and mild hirsutism. The baseline laboratory findings are presented in Table 1, with hypokalemia, diabetes, leukocytosis, high levels of serum cortisol, ACTH, and chromogranin A, and increased urine-free cortisol (UFC) secretion. There was no suppression of serum cortisol or UFC after a high-dose dexamethasone test. ACTH-dependent CS was diagnosed, and EAS was suspected. The patient’s family history was negative for endocrine diseases or genetic disorders.

Table 1

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Table 1. Laboratory results at diagnosis (April 2016).

The first-line cross-sectional imaging studies (chest, abdomen, and pelvis CT and MRI of the pituitary gland) did not reveal the source of ACTH. Only a symmetrical enlargement of adrenals was observed. 68Ga DOTA-TATE PET/CT revealed an oval lesion in the anterior mediastinum (1.9 × 1.3 cm) with a subtle overexpression of somatostatin receptors (SUV max. 2.8, Figures 1A, B). The chest MRI confirmed a mass 1.5 × 2.0 × 2.5 cm, with high T2-weighted signal and high contrast enhancement, suggestive of NET. The patient was given ketoconazole (600 mg daily), spironolactone, potassium supplementation, antihypertensive drugs, and thromboembolic prophylaxis. In June 2016, thoracoscopic removal of the mediastinal tumor was performed. In the histopathological examination, the tumor was encapsulated, without evidence of invasion, and no lymph node metastases were described. The immunophenotype of the tumor was as follows: CgA (+), Syn (+), CKAE1+E3 (+) “dot-like”, S100 (-), calcitonin (-), EMA (+/-), Ki67 3% to 4% in hot spots, no necrosis, mitotic index 0/10HPF with conclusion: thymic NET—typical carcinoid (low-grade). The presence of paraganglioma was also taken into consideration, as such cases were described (17). However, the significant reaction with cytokeratin and lack of S100 protein expression made this diagnosis less probable.

Figure 1

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Figure 168Ga-DOTATATE PET/CT scans. (A, B) Before the first surgery (April 2016). (C, D) Before the second surgery (May 2021). (E, F) Before the third surgery (January 2023).

The postoperative morning serum cortisol concentration was below 5 µg/dL, indicating biochemical remission. The patient received hydrocortisone substitution for a month. The clinical signs of CS disappeared, and there was a normalization of UFC.

During 5 years of follow-up, the patient got pregnant and delivered a healthy child. Genetic counseling was performed, and no germline mutation of MEN1 gene was identified. Other clinical manifestations of MEN1 (like primary hyperparathyroidism and pituitary secreting tumors) were excluded.

In May 2021, the patient experienced a sudden recurrence of CS symptoms. The laboratory findings confirmed severe hypercortisolism (Table 2); therefore, treatment with steroid inhibitor metyrapone was administered. The patient tolerated only 750 mg daily; there were side effects (skin rash and tachycardia) with higher doses. The chest MRI revealed no recurrence in the location of the primary tumor, only a lesion in the right breast (1.2 × 1.0 × 1.1 cm) with atypical contrast enhancement. The 68Ga-DOTA-TATE PET/CT result showed a subtle overexpression of the tracer (SUV max 1.9) in the right breast (Figures 1C, D). Breast ultrasonography confirmed a hypoechogenic, hypervascular mass in the right breast, BIRADS 3/4, diagnosed as NET in the breast biopsy. The tumor was removed in July 2021 without complications. The histopathological samples were compared with the primary lesion, confirming the metastasis from thymic NET to the breast—tumor size 0.7 × 1.5 cm, clear surgical margins (8 mm) with Ki67 3% (NET G2), and no lymph node metastases. After the breast surgery, the cortisol levels normalized in blood and urine and the CS symptoms disappeared. 18F-FDG PET/CT and 68Ga-DOTA-TATE PET/CT were performed, showing no pathological increase of radiotracer uptake in post-operative locations or mediastinal lymph nodes. The patient consulted with the oncology team, and no adjuvant therapy was recommended.

Table 2

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Table 2. Laboratory results during 7 years of observation.

The next recurrence of the disease occurred in February 2023, with the symptoms developing suddenly during a very short period (1 to 2 weeks), additionally with significant mental deterioration (concentration disorders, anxiety, severe mood swing). The laboratory findings confirmed excessive hypercortisolism (Table 2). The patient was given osilodrostat (the initial dose was 20 mg daily but later reduced to 10 mg daily for 2 weeks until surgery) and symptomatic treatment with good clinical and biochemical effect. The 68Ga-DOTA-TATE PET/CT result showed a slightly increased uptake of the tracer in the left mediastinum, between cervical vessels, 0.9 × 1.2 cm (Figures 1E, F)—probably a local recurrence. Thoracotomy was performed in February 2023, with subsequent clinical and biochemical improvement (Table 2). In the histopathological examination, mediastinal NET G1 was diagnosed, without necrosis, mitotic activity 0/2 mm2, immunophenotype CgA (+), CD56 (+), Ki 67 1%, CK AE1/AE3 (+), CD117 (+), p40 (-), TdT (-), PAX8 (-), and the presence of tumor cell embolism in the vessels. One metastatic lesion was found in the pericardium (the maximal dimension of the tissue was 13 mm, resected radically). Two metastatic lesions in the fat tissue were found (one tissue fragment from the mediastinum, max. 16 mm diameter, and the second tissue fragment was surrounding the jugular vein, max. diameter up to 40 mm, both resected radically). Two of the 10 resected lymph nodes had metastatic lesions: one from the area of the jugular vein, diameter 11 mm, with capsular invasion, and the second lymph node N2R with capsular invasion, both resected radically. The symptoms of hypercortisolism disappeared, and the cortisol values were normalized after the operation. The patient is currently under careful monitoring, without signs of clinical or biochemical recurrence. 68Ga-DOTA-TATE PET/CT is performed every 6 months.

3 Discussion

Our case is representative for thymic NETs causing EAS presented in literature, but it also shows some distinct features, giving new insight into this rare condition.

In recent series, ACTH-secreting thymic NETs occurred often in young adults, like our patient. The typical age of presentation is 21–35 years in the largest case series, and 7.4% were children under 15 years (1213). In contrast, the former series of thymic NETs showed a peak incidence in the sixth decade of life (11).

ACTH-secreting thymic NETs show a slight male preponderance (58.6%); however, the patient’s gender does not seem to relate with the disease outcome (12). There was only an association between male sex and larger tumor size preoperatively as found in one case series (13).

Thymic NETs causing EAS are very rarely associated with MEN1; we have also excluded it in our patient. On the contrary, 30% of thymic NETs not associated with CS are found in patients with MEN1, mostly male smokers (18). It is not clear why thymic NETs with EAS are less likely caused by MEN1 gene mutation, but the possibility of this genetic predisposition should always be taken into consideration.

Thymic NETs associated with EAS are generally considered aggressive, presenting significant cellular atypia in the histopathological examination (19). However, the biology of the tumors is variable. In the histopathological examination of 92 thymic NETs secreting ACTH, the most common subtype was atypical NET (46.7%), while 30.4% of the cases were typical NETs and 21.7% were carcinomas, with the median Ki-67 10%, ranging from 1% to 40%. The median tumor size among 112 patients was 4.7 cm, ranging from 1 to 20 cm, and 55.7% of patients had metastases at presentation (12). It proves the significant heterogeneity of the disease.

Our patient had typical NET with small dimensions and localized disease at the time of diagnosis. Despite this, we observed aggressive Cushing’s syndrome with a short duration of symptoms and life-threatening hypokalemia. It has been observed that there is no correlation between tumor size and hormone levels (12). Thymic NETs associated with EAS are often large, which simplifies the diagnosis and localization. However, in the case of incidental sellar mass or small thymic tumor, the differential diagnosis might be difficult. The highest sensitivity in distinguishing thymic EAS from Cushing’s disease was documented in inferior petrosal sinus sampling and corticotropin-releasing hormone (CRH) stimulation test (1220).

In severe cases, when small ACTH-secreting NET needs to be found urgently, PET/CT is a very helpful diagnostic tool. In a prospective study comprising 20 patients with histologically proven EAS, the 68Ga-DOTATATE PET/CT result correctly identified the tumor in 75%, with SUV max. ranging from 1.4 to 20.7, while the 18F-FDG PET/CT findings had a slightly worse result (identified 60% tumors), with SUV max. ranging from 1.8 to 10.0. Those methods are believed to be complementary in case of localization and discrimination of EAS. The 68Ga-DOTATATE PET/CT result revealed tumor in six cases with a negative 18F-FDG PET/CT result, while the 18F-FDG PET/CT procedure was diagnostic in three cases with a negative 68Ga-DOTATATE uptake; the combined sensitivity of both methods was 90% (10). The typical first-line diagnostic modalities’ (CT and MRI) sensitivities range from 52% to 66% (9). Our case remains in accordance with those results, showing difficulties in localizing the ACTH source in first-line radiological methods and with 68Ga-DOTATATE PET/CT being the most useful diagnostic tool. It should also be noted that the 68Ga-DOTATATE uptake was only mildly elevated both in primary tumor and its recurrences despite excessive hormonal activity. We did not perform 18F-FDG PET/CT until second operation, as it was believed to be rather helpful in poorly differentiated tumors and 68Ga-DOTATATE PET/CT was diagnostic. Later, we performed it in search for other metastatic tumors, but the examination showed no tumor spread.

The recommended treatment of thymic NETs regarded radically resectable is thymectomy by median sternotomy or thoracotomy and lymph node dissection (112122). According to the last version of the ESMO Guidelines, available literature suggests no benefit from adjuvant therapy in ThCs. The majority of the authors of the Guidelines panel suggest individually discussing eventual postoperative therapies, including RT and/or systemic therapies, balancing the pros and cons only in selected patients with advanced stage R0 or R1-2 resection (22). Data on systemic therapies in thymic NETs are scarce; therefore, they should be discussed in a multidisciplinary expert team in case of morphologically progressive tumors, high tumor burden, or refractory hormonal syndromes. Somatostatin analogs are recommended as the first-line systemic therapy in typical carcinoids (22). We considered the adjuvant therapy with somatostatin analogs; however, due to the low uptake in PET examination and complete resolution of symptoms as well as the radical type of surgical removal, we did not decide to initiate such therapy. Other systemic treatment options include everolimus (second line in typical carcinoids or first line in atypical carcinoids), chemotherapy, peptide receptor radionuclide therapy (PRRT), and interferon-α (2223). There is also data on the benefits of combining long-acting lanreotide with temozolomide in progressive thymic NETs (24).

Due to the variable availability of steroid inhibitors during the course of the disease, our patient received three different preparations at each disease relapse. Both ketoconazole and osilodrostat were well tolerated and reduced the hypercortisolism within a few days, but metyrapone caused significant side effects (see below—”Patient’s perspective”), and it was not possible to normalize the cortisol values with this steroid inhibitor. It is worth noting that when using the most recent steroid inhibitor—osilodrostat—we initiated the therapy with a high dose without a previous dose titration. This strategy might be used in the case of severe hypercortisolism and proved effective and safe in our patient (25).

Most commonly, metastases from thymic NET producing ACTH are localized in lymph nodes, bone, lung, pleura, and, less commonly, liver and parotid gland (13). There are very few cases of EAS-related thymic NETs with breast metastases described in the literature, with some histopathological variability (one case related to atypical carcinoid, another to combined large-cell neuroendocrine carcinoma and atypical carcinoid, and third case of neuroendocrine carcinoma). All of them were female patients between 24 and 36 years of age, with mediastinal lymph nodes metastases at the time of presentation; one also had distant metastases to the bones (1315). Contrary to the reported cases, our patient had typical carcinoid (confirmed by three independent pathologists from different centers) but similarly presented with severe hypercortisolism. It suggests that there is no connection between tumor differentiation and the severity of hypercortisolism. Interestingly, in a review of 661 patients with metastatic NETs from Sweden, there were 20 patients with NETs and breast metastases, and among them only one case of thymic NET (Ki 67 12%), but without EAS. A total of 11 patients with breast metastases had a primary tumor in the small intestine and eight in the lung (16).

Our case underlines the necessity of long-term follow-up in EAS, as the recurrences occurred 5 and 7 years after the initial successful treatment. According to guidelines, follow-up after treatment of thymic NETs should be life-long (22).

The strength of our report is the presentation of a thymic NET with metastasis to the breast, diagnosed and treated with many currently available tools and with a long period of follow-up. The limitation is the low number of other similar cases to compare, which is a consequence of the rarity of this disease.

In conclusion, our case proves that thymic NETs with EAS might present in young patients with well-differentiated character in histopathological examination and severe, life-threatening hypercortisolism despite the small size of the primary lesion. 68Ga-DOTATATE PET/CT is a very helpful tool to localize the tumor. Finally, life-long follow-up should be performed despite complete remission after surgery.

4 Patient’s perspective

The first symptoms that I observed were face edema and mood changes. I rapidly lost muscle mass (approximately 6 kg in 2 weeks), and I was not able to climb stairs, especially with my child’s pram. The most difficult to accept were changes in my appearances—hirsutism, losing hair, changes of my facial features. My sense of pain (for example, during medical procedures) was diminished. Other disruptive symptoms were intensive sweating, increased appetite, thirst, brain fog, and digestive problems. At every relapse, the disease manifestations were fluctuating, all of them intensifying at the same time, which was very difficult for me. Also stress evoked disease symptoms. I experienced a strange feeling of warm during cortisol outbursts.

As for the treatment, I did not tolerate metyrapone well. I had skin rash, anxiety attacks with heart palpitations, and a metallic taste in my mouth. Other drugs (ketoconazole, osilodrostat) were better for me.

After operations of the relapses, the symptoms diminished very quickly, especially the most difficult ones. My blood pressure and glycemia normalized within a few days. Other manifestations, like loss of hair or skin changes, persisted up to 3 months.

Data availability statement

The datasets presented in this article are not readily available because the data are potentially identifiable. Requests to access the datasets should be directed to Aleksandra Zdrojowy-Wełna, aleksandra.zdrojowy-welna@umw.edu.pl.

Ethics statement

This study was exempt from ethical approval procedures being a case report of a single patient who has voluntarily provided oral and written consent to participate in the study and to have her case published for the sake of helping us better understand the clinical picture and the course of thymic neuroendocrine tumors with EAS and share it with the medical community for awareness about it. Written informed consent was obtained from the participant/patient(s) for the publication of this case report.

Author contributions

AZ-W: Conceptualization, Data curation, Investigation, Methodology, Software, Writing – original draft. MB: Conceptualization, Supervision, Writing – review & editing. JS: Data curation, Investigation, Methodology, Writing – review & editing. AJ-P: Data curation, Investigation, Writing – review & editing. JK-P: Conceptualization, Data curation, Investigation, Methodology, Supervision, Writing – original draft.

Funding

The author(s) declare that no financial support was received for the research, authorship, and/or publication of this article.

Acknowledgments

We would like to thank Prof. Barbara Górnicka and Prof. Michał Jeleń for their collaboration throughout the patient’s treatment.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

The handling editor AJ declared a past co-authorship with the author MB.

The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

 

Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fonc.2025.1492187/full#supplementary-material

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Keywords: ectopic Cushing`s syndrome, thymic neuroendocrine tumor, thymic NET, ectopic ACTH secretion, case report

Citation: Zdrojowy-Wełna A, Bolanowski M, Syrycka J, Jawiarczyk-Przybyłowska A and Kuliczkowska-Płaksej J (2025) Case Report: Thymic neuroendocrine tumor with metastasis to the breast causing ectopic Cushing’s syndrome. Front. Oncol. 15:1492187. doi: 10.3389/fonc.2025.1492187

Received: 11 September 2024; Accepted: 31 January 2025;
Published: 25 February 2025.

Edited by:

Aleksandra Gilis-Januszewska, Jagiellonian University Medical College, Poland

Reviewed by:

Piero Ferolla, Umbria Regional Cancer Network, Italy
Lukasz Dzialach, Warsaw Medical University, Poland

Copyright © 2025 Zdrojowy-Wełna, Bolanowski, Syrycka, Jawiarczyk-Przybyłowska and Kuliczkowska-Płaksej. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Aleksandra Zdrojowy-Wełna, aleksandra.zdrojowy-welna@umw.edu.pl

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Personalized Noninvasive Diagnostic Algorithms Based on Urinary Free Cortisol in ACTH-dependant Cushing’s Syndrome

Julie Lavoillotte, Kamel Mohammedi, Sylvie Salenave, Raluca Maria Furnica, Dominique Maiter, Philippe Chanson, Jacques Young, Antoine Tabarin
The Journal of Clinical Endocrinology & Metabolism, Volume 109, Issue 11, November 2024, Pages 2882–2891
https://doi.org/10.1210/clinem/dgae258

Abstract

Context

Current guidelines for distinguishing Cushing’s disease (CD) from ectopic ACTH secretion (EAS) are questionable, as they use pituitary magnetic resonance imaging (MRI) as first-line investigation for all patients. CRH testing is no longer available, and they suggest performing inferior petrosal sinus sampling (BIPPS), an invasive and rarely available investigation, in many patients.

Objective

To establish noninvasive personalized diagnostic strategies based on the probability of EAS estimated from simple baseline parameters.

Design

Retrospective study.

Setting

University hospitals.

Patients

Two hundred forty-seven CD and 36 EAS patients evaluated between 2001 and 2023 in 2 French hospitals. A single-center cohort of 105 Belgian patients served as external validation.

Results

Twenty-four-hour urinary free cortisol (UFC) had the highest area under the receiver operating characteristic curve for discrimination of CD from EAS (.96 [95% confidence interval (CI), .92–.99] in the primary study and .99 [95% CI, .98–1.00] in the validation cohort). The addition of clinical, imaging, and biochemical parameters did not improve EAS prediction over UFC alone, with only BIPPS showing a modest improvement (C-statistic index .99 [95% CI, .97–1.00]). Three groups were defined based on baseline UFC: < 3 (group 1), 3–10 (group 2), and > 10 × the upper limit of normal (group 3), and they were associated with 0%, 6.1%, and 66.7% prevalence of EAS, respectively. Diagnostic approaches performed in our cohort support the use of pituitary MRI alone in group 1, MRI first followed by neck-to-pelvis computed tomography scan (npCT) when negative in group 2, and npCT first followed by pituitary MRI when negative in group 3. When not combined with the CRH test, the desmopressin test has limited diagnostic value.

Conclusion

UFC accurately predicts EAS and can serve to define personalized and noninvasive diagnostic algorithms.

Read the article here: https://academic.oup.com/jcem/article/109/11/2882/7645065

Adrenocorticotropin-Dependent Ectopic Cushing’s Syndrome: A Case Report

Abstract

Paraneoplastic syndromes are rare and diverse conditions caused by either an abnormal chemical signaling molecule produced by tumor cells or a body’s immune response against the tumor itself. These syndromes can manifest in a variable, multisystemic and often nonspecific manner posing a diagnostic challenge.

We report the case of an 81-year-old woman who exhibited severe hypokalemia, metabolic alkalosis, and worsening hyperglycemia. The investigation was consistent with adrenocorticotropin (ACTH)-dependent Cushing’s syndrome and, eventually, the patient was diagnosed with stage IV primary small-cell lung cancer (SCLC).

SCLC is known to be associated with paraneoplastic syndromes, including Cushing’s syndrome caused by ectopic adrenocorticotropin (ACTH) secretion. Despite being associated with very poor outcomes, managing these syndromes can be challenging and may hold prognostic significance.

Introduction

Adrenocorticotropin (ACTH)-dependent Cushing’s syndrome (CS) is caused by excessive ACTH production by corticotroph (Cushing’s disease (CD)) or nonpituitary (ectopic) tumors, leading to excessive cortisol production. Ectopic ACTH syndrome (EAS) is a rare condition, accounting for 10 to 20% of all cases of ACTH-dependent CS and 5 to 10% of all types of CS [1]. The normal glucocorticoid-induced suppression of ACTH is reduced in ACTH-dependent CS, especially with ectopic ACTH production. Studies show that a wide variety of neoplasms, usually carcinomas rather than sarcomas or lymphomas, have been associated with EAS. Most cases are caused by neuroendocrine tumors of the lung, pancreas, or thymus, in which the hypercortisolism state is not apparent clinically, resulting, all too often, in delayed diagnosis [2,3].

Current diagnostic tests for EAS aim to confirm high cortisol levels, the absence of a cortisol circadian rhythm, as well as the reduced response to negative feedback from glucocorticoid administration, and imaging to identify the site of ACTH production.

Prompt diagnosis and management are crucial in EAS, highlighting the importance of physician awareness and early recognition of this syndrome.

Treatment options depend on the underlying tumor. Surgical removal is often the primary approach, followed by radiation therapy or chemotherapy. Additionally, medications to control cortisol levels may be necessary to manage the various comorbid conditions associated with CS, such as cardiovascular disease, diabetes, electrolyte imbalances, infections and thrombotic risk [4,5].

Case Presentation

We report the case of an 81-year-old woman with a fully active performance status (ECOG 0) and a medical history of diabetes, hypertension, dyslipidemia, and depressive disorder. She was admitted to an internal medicine ward due to an acute hydroelectrolytic disorder, including metabolic alkalosis, severe hypokalemia (2 mmol/L), hypochloremia (85 mmol/L), hypocalcemia (0.95 mmol/L), hypophosphatemia (1.4 mg/dL), hypomagnesemia (0.9 mg/dL), and hyperlactatemia (5.8 mmol/L), after she reportedly self-medicated herself with higher doses of metformin (four to five pills a day) due to high blood glucose levels. The patient presented with asthenia, nausea, vomiting, and diarrhea for three days and reported uncontrolled blood glucose levels for the last eight days.

The physical examination was unremarkable, without any altered mental status or signs of infection. Arterial blood gas samples showed metabolic alkalemia (pH 7.59) and hyperlactatemia, associated with severe hypokalemia, normal bicarbonate (27 mmol/L), and mildly elevated glycemia and ketonemia (232 mg/dL and 1.7 mmol/L, respectively). Lab tests confirmed the serum potassium levels as well as the other aforementioned electrolyte disturbances. Kidney function and hepatic enzymes were normal. Considering the possible relationship between the electrolyte disorder and the gastrointestinal presentation, the patient was given intravenous (IV) fluids and received potassium and magnesium replacement therapy.

Despite receiving 200 milliequivalents (mEq) of IV potassium chloride and 4 grams of magnesium sulfate, in the first 48 hours, the ion deficits persisted. Given the persistent electrolyte derangement, the patient was admitted to the Internal Medicine ward for etiological investigation and monitoring of ionic correction. The initial period was remarkable for refractory hypokalemia and uncontrolled diabetes under respective therapeutic measures, including 80 to 130 mEq of IV potassium chloride and progressive titration of spironolactone to 200 mg a day. Laboratory investigation revealed high parathormone levels (PTHi 167 pg/mL; reference range: 10-65 pg/mL), vitamin D deficiency (3.3 ng/mL; reference range >20 ng/mL) and apparent ACTH-dependent hypercortisolism (serum cortisol 80.20 ug/dL; ACTH 445 pg/mL), as well as high urinary potassium and glucose concentrations (190 mEq/24 h and 21161 mg/24 h). A dexamethasone suppression test was performed twice (standard low and high dose) without any changes in cortisol levels, leading to the suspicion of a CS caused by abnormally high ACTH production. Cranioencephalic computed tomography (CT) and magnetic resonance imaging (MRI) were performed, excluding the presence of pituitary anomalies. A follow-up whole-body CT scan was performed, revealing a suspicious pulmonary mass in the left lower lobe, associated with ipsilateral hilar lymphadenopathy and hepatic and adrenal gland lesions suggestive of secondary involvement. An endobronchial ultrasound bronchoscopy and biopsy were performed, documenting anatomopathological findings of small-cell lung carcinoma with a Ki67 expression of 100% (Figures 13).

Pulmonary-mass-(SCLC)-in-the-left-lower-lobe-with-ipsilateral-hilar-lymphadenopathy-and-pleural-effusion.
Figure 1: Pulmonary mass (SCLC) in the left lower lobe with ipsilateral hilar lymphadenopathy and pleural effusion.

SCLC: small-cell lung cancer.

Secondary-involvement-of-the-liver-with-hypodense-multilobar-hepatic-lesions-(arterial-phase).
Figure 2: Secondary involvement of the liver with hypodense multilobar hepatic lesions (arterial phase).
Bilateral-suprarenal-lesions-suggestive-of-secondary-involvement.
Figure 3: Bilateral suprarenal lesions suggestive of secondary involvement.

The patient was referred to oncology, and chemotherapy was deferred, considering the infectious risk associated with hypercortisolism.

The patient started metyrapone 500 mg every eight hours, resulting in a reduction in cortisol levels and control of hypokalemia. Later on, a fluorodeoxyglucose-positron emission tomography (FDG-PET) scan was performed, confirming disseminated disease with additional bone involvement. Unfortunately, despite endocrinological stabilization, the patient’s condition worsened, and she ended up dying one month after the diagnosis.

Discussion

When this patient was admitted, it was assumed that the metabolic alkalosis and various electrolyte disturbances were related to the gastrointestinal presentation and hyperlactatemia secondary to metformin overdose. However, the unusual persistence and refractory hypokalaemia raised some concerns that an alternative etiology might be involved and incited subsequent testing.

The high cortisol levels were unexpected given the subclinical presentation, which seems to be more frequent in cases of EAS. In fact, because of this, the true incidence of EAS is unknown and probably underdiagnosed since patients often have subclinical presentations and do not exhibit catabolic features.

Since the patient wasn’t on any steroid medication, the association between the high cortisol and ACTH levels, non-responsive to the dexamethasone suppression test, along with the absence of a pituitary lesion, raised suspicion of a probable EAS, which was later confirmed by the body CT scan and endobronchial ultrasound (EBUS).

EAS is a rare disease with a poor prognosis. It reportedly occurs in 3.2 to 6% of neuroendocrine neoplasms, and the tumor often originates in the lung, thyroid, stomach, and pancreas. Locoregional and/or distant metastasis can be seen at the time of diagnosis in 15% of typical carcinoids and about half of atypical carcinoids with visible primaries [6,7].

The presence of a typical CS presentation, with or without electrolyte abnormalities, should raise suspicion and serum levels of both ACTH and cortisol should be assessed to determine if they are elevated and to distinguish between an ACTH-dependent (pituitary or nonpituitary ACTH-secreting tumor) and an independent mechanism (e.g., from an adrenal source). The diagnosis of CS is established when at least two different first-line tests are unequivocally abnormal and cannot be explained by any other conditions that cause physiologic hypercortisolism. Additional evaluation is performed to rule out a pituitary origin (with brain MRI) and to assess for a possible ectopic ACTH-secreting tumor.

In the aforementioned case, the production of ACTH was caused by primary neuroendocrine SCLC. The recommended approach to EAS involves the initial normalization of serum cortisol levels and the treatment of related comorbidities before performing a complete diagnostic evaluation and addressing the underlying cause [5-7]. This approach seems to improve survival and prevent complications such as sepsis following a combined steroid-induced immunosuppression and chemotherapy-induced agranulocytosis [6,7].

Direct therapies vary according to the tumor, but surgery is usually the first line of treatment (transsphenoidal surgery in cases of CD or tumor resection in cases of non-metastatic EAS). However, our patient presented with stage IV SCLC with EAS, in which chemotherapy remains the first-line treatment. SCLC patients with EAS have a poorer prognosis than those without EAS, with a life expectancy of only three to six months. This makes early diagnosis more important [2,7], as controlling the high cortisol levels and then administering systemic chemotherapy may achieve longer survival [8].

Apart from systemic chemotherapy, ketoconazole (widely accepted but highly toxic), metyrapone, mitotane (adrenocortical suppressant drug with significant side effects), and mifepristone (glucocorticoid antagonist, mainly used for the treatment of hyperglycemia in CS) can be used to reduce circulating glucocorticoids. Moreover, thromboprophylaxis and Pneumocystis jirovecii pneumonia prophylaxis should be started.

Because ketoconazole may increase the risk of chemotherapy toxicity by inhibiting cytochrome P450 3A4, metyrapone has been reported to be a better choice [5,7].

Nonetheless, administration of chemotherapy in the setting of a hypercortisolism-induced immunosuppressive state, cancerous background and metabolic disorders featuring electrolyte disturbance and hyperglycemia, aggravate the condition and can be life-threatening. Thus, a palliative approach can sometimes be reasonable.

Conclusions

The diagnosis of CS is a three-step process that includes its suspicion based on the patient’s laboratory and semiologic findings, the documentation of hypercortisolism, and the identification of its cause, which can be either ACTH-dependent or independent.

The ectopic secretion of ACTH (EAS) by nonpituitary tumors is a relatively rare cause of CS and often presents as paraneoplastic syndromes, adding therapeutic and prognostic concerns.

This case, in particular, highlights the importance of seeking alternative explanations for common electrolyte disturbances, particularly when they don’t resolve promptly. Clinicians should be aware of EAS and its frequent subclinical presentation in order to initiate the diagnostic workup as soon as suspicion arises.

References

  1. Hayes AR, Grossman AB: The ectopic adrenocorticotropic hormone syndrome: rarely easy, always challenging. Endocrinol Metab Clin North Am. 2018, 47:409-25. 10.1016/j.ecl.2018.01.005
  2. Ilias I, Torpy DJ, Pacak K, Mullen N, Wesley RA, Nieman LK: Cushing’s syndrome due to ectopic corticotropin secretion: twenty years’ experience at the National Institutes of Health. J Clin Endocrinol Metab. 2005, 90:4955-62. 10.1210/jc.2004-2527
  3. Lacroix A, Feelders RA, Stratakis CA, Nieman LK: Cushing’s syndrome. Lancet. 2015, 29:913-27. 10.1016/S0140-6736(14)61375-1
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  5. Nieman LK, Biller BM, Findling JW, Murad MH, Newell-Price J, Savage MO, Tabarin A: Treatment of Cushing’s syndrome: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2015, 100:2807-31. 10.1210/jc.2015-1818
  6. Bostan H, Duger H, Akhanli P, et al.: Cushing’s syndrome due to adrenocorticotropic hormone-secreting metastatic neuroendocrine tumor of unknown primary origin: a case report and literature review. Hormones (Athens). 2022, 21:147-54. 10.1007/s42000-021-00316-z
  7. Richa CG, Saad KJ, Halabi GH, Gharios EM, Nasr FL, Merheb MT: Case-series of paraneoplastic Cushing syndrome in small-cell lung cancer. Endocrinol Diabetes Metab Case Rep. 2018, 2018:4. 10.1530/EDM-18-0004
  8. Zhang HY, Zhao J: Ectopic Cushing syndrome in small cell lung cancer: a case report and literature review. Thorac Cancer. 2017, 8:114-7. 10.1111/1759-7714.12403

From https://www.cureus.com/articles/198133-adrenocorticotropin-dependent-ectopic-cushings-syndrome-a-case-report#!/

Challenging Case of Ectopic ACTH Secretion from Prostate Adenocarcinoma

Abstract

Cushing’s syndrome (CS) secondary to ectopic adrenocorticotrophic hormone (ACTH)-producing prostate cancer is rare with less than 50 cases reported. The diagnosis can be challenging due to atypical and variable clinical presentations of this uncommon source of ectopic ACTH secretion. We report a case of Cushing’s syndrome secondary to prostate adenocarcinoma who presented with symptoms of severe hypercortisolism with recurrent hypokalaemia, limb oedema, limb weakness, and sepsis. He presented with severe hypokalaemia and metabolic alkalosis (potassium 2.5 mmol/L and bicarbonate 36 mmol/L), with elevated 8 am cortisol 1229 nmol/L. ACTH-dependent Cushing’s syndrome was diagnosed with inappropriately normal ACTH 57.4 ng/L, significantly elevated 24-hour urine free cortisol and unsuppressed cortisol after 1 mg low-dose, 2-day low-dose, and 8 mg high-dose dexamethasone suppression tests. 68Ga-DOTANOC PET/CT showed an increase in DOTANOC avidity in the prostate gland, and his prostate biopsy specimen was stained positive for ACTH and markers for neuroendocrine differentiation. He was started on ketoconazole, which was switched to IV octreotide in view of liver dysfunction from hepatic metastases. He eventually succumbed to the disease after 3 months of his diagnosis. It is imperative to recognize prostate carcinoma as a source of ectopic ACTH secretion as it is associated with poor clinical outcomes, and the diagnosis can be missed due to atypical clinical presentations.

1. Introduction

Ectopic secretion of adrenocorticotropic hormone (ACTH) is responsible for approximately 10–20% of all causes of Cushing syndrome [1]. The classic sources of ectopic ACTH secretion include bronchial carcinoid tumours, small cell lung carcinoma, thymoma, medullary thyroid carcinoma (MTC), gastroenteropancreatic neuroendocrine tumours (NET), and phaeochromocytomas [2]. Ectopic adrenocorticotropic syndrome (EAS) is diagnostically challenging due to its variable clinical manifestations; however, prompt recognition and treatment is critical. Ectopic ACTH production from prostate carcinoma is rare, and there are less than 50 cases published to date. Here, we report a case of ectopic Cushing’s syndrome secondary to prostate adenocarcinoma who did not present with the typical physical features of Cushing’s syndrome, but instead with features of severe hypercortisolism such as hypokalaemia, oedema, and sepsis.

2. Case Presentation

A 61-year-old male presented to our institution with recurrent hypokalaemia, lower limb weakness, and oedema. He had a history of recently diagnosed metastatic prostate adenocarcinoma, for which he was started on leuprolide and finasteride. Other medical history includes poorly controlled diabetes mellitus and hypertension of 1-year duration. He presented with hypokalaemia of 2.7 mmol/L associated with bilateral lower limb oedema and weakness, initially attributed to the intake of complementary medicine, which resolved with potassium supplementation and cessation of the complementary medicine. One month later, he was readmitted for refractory hypokalaemia of 2.5 mmol/L and progression of the lower limb weakness and oedema. On examination, his blood pressure (BP) was 121/78 mmHg, and body mass index (BMI) was 24 kg/m2. He had no Cushingoid features of rounded and plethoric facies, supraclavicular or dorsocervical fat pad, ecchymoses, and no purple striae on the abdominal examination. He had mild bilateral lower limb proximal weakness and oedema.

His initial laboratory findings of severe hypokalaemia with metabolic alkalosis (potassium 2.5 mmol/L and bicarbonate 36 mmol/L), raised 24-hour urine potassium (86 mmol/L), suppressed plasma renin activity and aldosterone, central hypothyroidism, and elevated morning serum cortisol (1229 nmol/L) (Table 1) raised the suspicion for endogenous hypercortisolism. Furthermore, hormonal evaluations confirmed ACTH-dependent Cushing’s syndrome with inappropriately normal ACTH (56 ng/L) and failure of cortisol suppression after 1 mg low-dose, 2-day low-dose, and 8 mg high-dose dexamethasone suppression tests (Table 2). His 24-hour urine free cortisol (UFC) was significantly elevated at 20475 (59–413) nmol/day.

Table 1 
Investigations done during his 2nd admission.
Table 2 
Diagnostic workup for hypercortisolism.

To identify the source of excessive cortisol secretion, magnetic resonance imaging (MRI) of the pituitary fossa and computed tomography (CT) of the thorax, abdomen, and pelvis were performed. Pituitary MRI was unremarkable, and CT scan showed the known prostate lesion with extensive liver, lymph nodes, and bone metastases (Figure 1). To confirm that the prostate cancer was the source of ectopic ACTH production, gallium-68 labelled somatostatin receptor positron emission tomography (PET)/CT (68Ga-DOTANOC) was done, which showed an increased DOTANOC avidity in the inferior aspect of the prostate gland (Figure 2). Immunohistochemical staining of his prostate biopsy specimen was requested, and it stained positive for ACTH and markers of neuroendocrine differentiation (synaptophysin and CD 56) (Figures 3 and 4), establishing the diagnosis of EAS secondary to prostate cancer.

Figure 1 
CT thorax abdomen and pelvis showing prostate cancer (blue arrow) with liver metastases (red arrow).
Figure 2 
Ga68-DOTANOC PET/CT demonstrating increased DOTANOC avidity seen in the inferior aspect of the right side of the prostate gland (red arrow).
Figure 3 
Hematoxylin and eosin staining showing acinar adenocarcinoma of the prostate featuring enlarged, pleomorphic cells infiltrating as solid nests and cords with poorly differentiated glands (Gleason score 5 + 4 = 9).
Figure 4 
Positive ACTH immunohistochemical staining of prostate tumour (within the circle).

The patient was started on potassium chloride 3.6 g 3 times daily and spironolactone 25 mg once daily with normalisation of serum potassium. His BP was controlled with the addition of lisinopril and terazosin to spironolactone and ketoconazole, and his blood glucose was well controlled with metformin and sitagliptin. To manage the hypercortisolism, he was treated with ketoconazole 400 mg twice daily with an initial improvement of serum cortisol from 2048 nmol/L to 849 nmol/L (Figure 5). Systemic platinum and etoposide-based chemotherapy was recommended for the treatment of his prostate cancer after a multidisciplinary discussion, but it was delayed due to severe bacterial and viral infection. With the development of liver dysfunction, ketoconazole was switched to intravenous octreotide 100 mcg three times daily as metyrapone was not readily available in our country. However, the efficacy was suboptimal with marginal reduction of serum cortisol from 3580 nmol/L to 3329 nmol/L (Figure 5). The patient continued to deteriorate and was deemed to be medically unfit for chemotherapy or bilateral adrenalectomy. He was referred to palliative care services, and he eventually demised due to cancer progression within 3 months of his diagnosis.

Figure 5 
The trend in cortisol levels on pharmacological therapy.

3. Discussion

Ectopic ACTH secretion is an uncommon cause of Cushing’s syndrome accounting for approximately 9–18% of the patients with Cushing’s syndrome [3]. Clinical presentation is highly variable depending on the aggressiveness of the underlying malignancy, but patients typically present with symptoms of severe hypercortisolism such as hypokalaemiaa, oedema, and proximal weakness which were the presenting complaints of our patient [4]. The classical symptoms of Cushing’s syndrome are frequently absent due to the rapid clinic onset resulting in diagnostic delay [5].

Prompt diagnosis and localisation of the source of ectopic ACTH secretion are crucial due to the urgent need for treatment initiation. The usual sources include small cell lung carcinoma, bronchial carcinoid, medullary thyroid carcinoma, thymic carcinoid, and pheochromocytoma. CT of the thorax, abdomen, and pelvis should be the first-line imaging modality, and its sensitivity varies with the type of tumour ranging from 77% to 85% [6]. Functional imaging such as 18-fluorodeoxyglucose-PET and gallium-68 labelled somatostatin receptor PET/CT can be useful in localising the source of occult EAS, determining the neuroendocrine nature of the tumour or staging the underlying malignancy [36]. As prostate cancer is an unusual cause of EAS, we proceeded with 68Ga-DOTANOC PET/CT in our patient to localise the source of ectopic ACTH production.

The goals of management in EAS include treating the hormonal excess and the underlying neoplasm as well as managing the complications secondary to hypercortisolism [3]. Prompt management of the cortisol excess is paramount as complications such as hyperglycaemia, hypertension, hypokalaemia, pulmonary embolism, sepsis, and psychosis can develop especially when UFC is more than 5 times the upper limit of normal [3]. Ideally, surgical resection is the first-line management, but this may not be feasible in metastatic, advanced, or occult diseases.

Pharmacological agents are frequently required with steroidogenesis inhibitors such as ketoconazole and metyrapone, which reduce cortisol production effectively and rapidly [36], the main drawback of ketoconazole being its hepatic toxicity. The efficacy of ketoconazole is reported to be 44%, metyrapone 50–75%, and ketoconazole-metyrapone combination therapy 73% [37]. Mitotane, typically used in adrenocortical carcinoma, is effective in controlling cortisol excess but has a slow onset of action [38]. Etomidate infusion can be used for short-term rapid control of severe symptomatic hypercortisolism and can serve as a bridge to definitive therapy [9]. Mifepristone, a glucocorticoid receptor antagonist, is indicated mainly in difficult to control hyperglycaemia secondary to hypercortisolism [8]. Somatostatin analogue has been proposed as a possible pharmacological therapy due to the expression of somatostatin receptors by ACTH secreting tumours [810]. Bilateral adrenalectomy should be considered in patients with severe symptomatic hypercortisolism and life-threatening complications who cannot be optimally managed with medical therapies, especially in patients with occult EAS or metastatic disease [38]. Bilateral adrenalectomy results in immediate improvement in cortisol levels and symptoms secondary to hypercortisolism [11]. However, surgical complications, morbidity, and mortality are high in patients with uncontrolled hypercortisolism [8], and our patient was deemed by his oncologist and surgeon to have too high a risk for bilateral adrenalectomy. For the treatment of prostate carcinoma, platinum and etoposide-based chemotherapies have been used, but their efficacy is limited with a median survival of 7.5 months [412]. The side effects of chemotherapy can be severe with an enhanced risk of infection due to both cortisol and chemotherapy-mediated immunosuppression. Prompt control of hypercortisolism prior to chemotherapy and surgical procedure is strongly suggested to attenuate life-threatening complications such as infection, thrombosis, and bleeding with chemotherapy or surgery as well as to improve prognosis [313].

There are rare reports of ectopic ACTH secretion from prostate carcinoma. These tumours were predominantly of small cell or mixed cell type, and pure adenocarcinoma with neuroendocrine differentiation are less common [45]. There is a strong correlation between the prognosis and the types of malignancy in patients with EAS, and patients with prostate carcinoma have a poor prognosis [4]. These patients had metastatic disease at presentation, and the median survival was weeks to months despite medical treatment, chemotherapy, and even bilateral adrenalectomy [4], as seen with our patient who passed away within 3 months of his diagnosis.

In conclusion, adenocarcinoma of the prostate is a rare cause of EAS. The diagnosis and management are complex and challenging requiring specialised expertise with multidisciplinary involvement. The presentation can be atypical, and it is imperative to suspect and recognise prostate carcinoma as a source of ectopic ACTH secretion. Prompt initiation of treatment is important, as it is a rapidly progressive and aggressive disease associated with intense hypercortisolism resulting in high rates of mortality and morbidity.

Data Availability

The data used to support the findings of this study are included within the article.

Conflicts of Interest

The authors declare that there are no conflicts of interest.

Acknowledgments

The authors would like to thank the Pathology Department of Changi General Hospital for their contribution to this case.

References

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Copyright © 2022 Wanling Zeng and Joan Khoo. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

From https://www.hindawi.com/journals/crie/2022/3739957/

Common Cushing’s Treatment, Somatostatin Analogs, May Sometimes Worsen Disease Course

Doctors often prescribe somatostatin analogs to manage the hormonal imbalance that characterizes Cushing’s syndrome. However, in rare situations these medicines have paradoxically made patients worse than better.

This recently happened with a 48-year-old Spanish woman whose Cushing’s syndrome was caused by an adrenal gland tumor that was producing excess adrenocorticotropic hormone (ACTH). Her case was recently reported in the study “Ectopic Cushing’s syndrome: Paradoxical effect of somatostatin analogs,” and published in the journal Endocrinología, Diabetes y Nutrición.

Cushing’s syndrome occurs when the body produces too much cortisol. This can happen for many reasons, including an oversupply of ACTH, the hormone responsible for cortisol production, due to a tumor in the pituitary gland.

But sometimes, tumors growing elsewhere can also produce ACTH. This feature, known as ectopic ACTH secretion (EAS), may also cause ACTH-dependent Cushing’s syndrome.

Two-thirds of EAS tumors are located in the thorax, and 8 to 15 percent are in the abdominal cavity. Only 5 percent of EAS tumors are located in the adrenal gland, and up to 15 percent of EAS tumors are never detected.

Doctors usually use cortisol synthesis inhibitors such as ketoconazole or Metopirone (metyrapone) to control EAS, due to their efficacy and safety profiles. But somatostatin analogs (SSAs) such as Somatuline (lanreotide) have also been used to treat these tumors. However, these drugs produce mixed results.

The woman in the case study, reported by researchers at the University Hospital Vall d’Hebron in Barcelona, Spain, had an EAS tumor on the adrenal gland. She experienced s life-threatening cortisol and ACTH increase after receiving high-dose Somatuline.

The patient had been recently diagnosed with hypertension, and complained of intense fatigue, muscular weakness, easy bruising and an absence of menstruation. Laboratory analysis revealed that she had triple the normal levels of free cortisol in the urine, elevated levels of plasma cortisol, and high ACTH levels. In addition, her cortisol levels remained unchanged after receiving dexamethasone. The patient was therefore diagnosed with ACTH-dependent Cushing syndrome.

To determine the origin of her high cortisol levels, the team conducted magnetic resonance imaging (MRI). They found no tumors on the most common places, including the pituitary gland, neck, thorax or abdomen. However, additional evaluation detected a small alteration on the left adrenal gland, suggesting that was the source of ectopic ACTH production.

The team initiated treatment with 120 mg of Somatuline, but a week later, her condition had worsened and become life-threatening. Doctors started Ketoconazole treatment immediately, three times daily. The affected adrenal gland was surgically removed, and tissue analysis confirmed the diagnosis. The patient’s clinical condition improved significantly over the follow-up period.

“We highlight the need to be aware of this rare presentation of EAS, and we remark the difficulties of EAS diagnosis and treatment,”  researchers wrote.

The team could not rule out the possibility that the patient’s clinical development was due to the natural course of the disease. However, they believe “she had a paradoxical response on the basis of her dramatical worsening just after the SSAs administration, associated to an important rise in ACTH and UFC levels.”

For that reason, researchers think a new version of SSAs, such as Signifor (pasireotide) — which has improved receptor affinity — could provide better therapeutic response.

From https://cushingsdiseasenews.com/2017/11/09/paradoxical-effects-of-somatostatin-analogs-on-adrenal-ectopic-acth-tumor/